Author: John Whitney (jjw@linuxmail.org)
License: GNU General Public License v2

  Deltup is a source package updater which enables users to apply a delta patch to the previous version of a package, as well as making delta patches for others to use.  This decreases download times significantly.  The package/patch ratio is typically 10:1, 20:1, and in some cases I've seen, higher than 80:1!
  See the GENTOO file for instructions and tips.
  Also included is a program called edelta which is a Gentoo (www.gentoo.org) frontend to deltup.  edelta currently is an alias for deltup -d {distfiles dir).

You can download patches for your Gentoo system at:
  http://sourceforge.net/projects/deltup/

Here are some examples of it's use:
  #use this command to create a mozilla-1.3b to mozilla-1.3 patch called
  #mozilla-1.3b-1.3.dtu in the current directory
    edelta -m mozilla-source-1.3b.tar.gz mozilla-source-1.3.tar.bz2 mozilla-1.3b-1.3.dtu
  #you can tar patches together so both can be applied with one command
    tar -cf mydoublepatch.dtu mozilla-1.3b-1.3.dtu xscreensaver-4.08-4.09.dtu
  #and here is how to apply this patch to another system that needs upgrading
    edelta -p mydoublepatch.dtu
  #and this does the same thing
    deltup -pd /usr/portage/distfiles mydoublepatch.dtu
  #apply three patches successively, without creating in-between packages
    edelta -pr patch1.dtu patch2.dtu patch3.dtu
  #find out what patches testpatch.dtu contains
    deltup -pi testpatch.dtu
  #md5sums are correct in almost every case, but to verify their accuracy
  #use the -e option
    edelta -me OOo_1.0.2_source.tar.bz2 OOo_1.0.3_source.tar.bz2 OO.dtu